Adverse drug events (ADEs) injure millions of patients and cost society billions of dollars each year. A strong culture of safety has been linked with quality outcomes across Intensive Care Unit environments. Infants in the neonatal intensive care unit (NICU) are at even higher risk of ADEs compared to adults. Multi-center research linking practices and outcomes in this environment is lacking. A large study is needed to clarify the associations between practices and outcomes in preparation for a prospective, multi-center medication safety practice implementation project. The central objective of this proposal is to link specific medication safety practices with short-term adverse events and long-term adverse clinical outcomes from a nationally representative electronic medical record (EMR). Dr. Smith will accomplish this objective by using an existing dataset from 25% of the infants admitted to a NICU in the United States. Through a partnership with the Pediatrix Medical Group, composed of 276 NICUs in the U.S. encompassing 900 neonatologists, he will use a comprehensive inventory tool to assess baseline medication safety practices, ADE reporting, ADE response strategies, and ADE outcomes across NICUs. He will then link these data with the broader Pediatrix EMR to evaluate associations between safety practices, short-term adverse event and long-term adverse clinical outcomes including mortality and length of stay. This proposal will: 1) provide the first comprehensive understanding of how U.S. NICUs vary in their ADE prevention and response practices and 2) define for the first time both positive and negative associations between medication safety practices, ADEs, and clinical outcomes at the multi-center level. If this proposal is successful, we will identify best-practices that can be broadly implemented to improve outcomes in this vulnerable population.